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Category Archives: Bahan Ajar

A. True or False
1. In hypothesis testing, we assume that some population parameter takes on particular value before we sample. This assumption to be tested is called an alternative hypothesis (False- null hypothesis) Testing hypothesis – one sample test

A. True or False
1. The principal advantage of multiple regression over simple regression is that it allows us to use more of the information available to estimate the dependent variable ( True) Multiple Regression

Assume a binomial distribution where n = 5 and p= 0.60a.List the probabilities for value of x from 0 to 5b.Determine the mean and standard deviation(Statistical Technique in Business and Economic., Lind,Marchal, Wathen., Mc Graw Hill., Fourteent Edition., page 197., number 12) Soal jawab distribusi binomial no 1- 9 April 2013

The united states postal service reports 0.05 percent of first class mail within the same city is delivered within two days of the time of mailing. Six letter are randomly sent to different locations.a.What is the probability that all six arrive within two days?b.What is the probability that exactly five arrive within two days?c.Find the mean number of letters that will arrive within two days
d.Compute the variance and standar deviation of the number that will arrive within two days(Statistical Technique in Business and Economic., Lind,Marchal, Wathen., Mc Graw Hill., Fourteent Edition., page 197., number 14) soal jawab distribusi binomial no 2 – 9 april 2013Continue reading →

A cell phone company offers two plans to its subscribers. At the time new subscribers sign up, they are asked to provide some demographic information. The mean yearly income for a sample of 40 subscribers to plan A is $ 57,000 with a standard deviation of $ 9,200. This distribution is positively skewed, the actual coeffiecient of skewness is 2.11. For a sample of 30 subscribers to plan B mean income is $ 61,000 with a standard deviation os $ 7,100. The distribustion of subscribers is also positively skewed but not as severly. The coefficient is 1.54. At the 0.05 significance level, is it reasonable to conclude the mean income of those selecting plan B is larger? What is the p value? Do the coefficient of skewness affect the results of the hypotheseis test ? Why? Two sample test of hypothesis no 1(Lind, Marchal, Wathen., Statistical Technique in Business and Economics., Fourteenth Edition., McGraw-Hill., page 393, number 31)

The manufacturer of the X-15 steel belted radial truck tire claims that the mean mileage the tire can be dri9ven before the tread wear out is 60,000 miles. The population standard deviation of the mileage is 5,000 miles. Crosset Truck Company bought 48 tires and found that the mean mileage fo5r its trucks is 59,500. Is the Crosset’s experience different from that claimed bt yhe manufacturer at the 0.05 significance level?(Lind, Marchal, wathen., Statistical Techinique in Business and Economics., Mac Graw Hill., Fourteeth edition., page 340, number 5) The solution of one sample hypothesis no 1Continue reading →

A sample of 49 observations is taken from a normal population with a standard deviation of 10. The sample mean is 55. Determine the 99 persen confidence interval for the population mean Soal dan jawab penaksiran no 1(Lind, Marchal, Wathen., Statistical Techniques in Business and Economics., Mac Graw Hill., Fourteenth edition., Exercise 1 page 297)

A sample of 81 observations is taken from a normal distribution with a standard deviation of 5. The sample mean is 40. Detremine the 95% confidence interval for the population mean Soal dan jawab penaksiran no 2(Lind, Marchal, Wathen., Statistical Techniques in Business and Economics., Mac Graw Hill., Fourteenth edition., Exercise2 page 297)Continue reading →

Even though independent gasoline stations have been having a difficult time, Susan Helms has been thinking about starting her own independent gasoline station. Susan’s problem is to decide how large her station should be. The annual returns will depend on both size of her station and a number of marketing factors related to the oil industry and demand for gasoline. After a careful analysis, susan developed the following table

Size of first station

Good market ($)

Fair market ($)

Poor market ($)

Small

50,000

20,000

-10,000

Mediaum

80,000

30,000

-20,000

Large

100,000

30,000

-40,000

Very large

300,000

25,000

-160,000

a) Develop a decision table for this decision, like the one illustrated in Table A.2 eralier soal decision modelling no 1 a
b) What is the maximax decision?
c) What is the maximin decision?
d) What is the equally likely decision?
e) Develop a decision tree. Assume each outcome is equally likely then find the EMV? soal decision modelling no 1 b,c,d,e(Jay Heize, Barry Render., Operations Management., Pearson., Tenth Edition., problems A.2., page 714)Continue reading →